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03/23/2012 12:47 PM

Technology Spotlight: Cleans Dirty Water Using Renewable Energy

SustainableBusiness.com News

A start-up company in the water treatment business is commercializing a natural pasteurization process that cleans up dirty wastewater using renewable energy.

Based in San Leandro, California, Pasteurization Technology Group recently got a $1 million infusion from EIC Ventures, which invests in early stage companies.

Here's how it works: during the process of disinfecting wastewater, biogas is created as a natural by-product, which is used to power turbines. The hot exhaust air raises the temperature of the wastewater, which disinfects it. Once it's disinfected, the water can be recycled and used again.

More details: The hot exhaust air from the turbine (energy that is typically wasted) is passed through a series of heat exchangers that raise the temperature of the wastewater to a level that disinfects the wastewater stream.

Unlike commonly used wastewater disinfection approaches, this technology doesn't require toxic chemicals such as chlorine or electrical power and expensive lamps.

By channeling the typically wasted exhaust heat from a turbine to disinfect wastewater, PTG's process is an energy efficient, low cost solution.

Its process is one of a handful of technologies that passes California's stringent standards (Title 22) for disinfection of water for reuse.

"We're experiencing strong commercial interest for our renewable energy wastewater disinfection system because businesses are facing rising water, sewer and electrical costs associated with managing their wastewater output. We have a solution that handles their disinfection needs while also offsetting their power and water bills," says Greg Ryan, co-founder and CEO.

The company says it will begin commercial shipments this year. They have two versions of their product, one that processes up to 500,000 gallons of water a day, and a small, mobile version that can be running within 24 hours of delivery and handles 14,000 gallons a day.

Its target markets are municipal wastewater treatment plants, many of which are aging, over capacity, and facing rising energy costs. Other markets are food, beverage, and oil & gas industries that consume large volumes of water.

The company will pitch to investors at the upcoming Cleantech Forum in San Francisco, March 26-28.